CODE EXAMPLE FOR SWIFT

swift create uinavigationcontroller programmatically

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    guard let windowScene = (scene as? UIWindowScene) else { return }

    window?.windowScene = windowScene
    window?.makeKeyAndVisible()

    let viewController = ViewController()
    let navViewController = UINavigationController(rootViewController: viewController)
    window?.rootViewController = navViewController
}